There is an association between elevated Type II Diabetes Mellitus (T2DM) risk and low serum levels of vitamin D. It is important to examine whether Vitamin D can enhance oral glucose tolerance in individuals at risk for developing T2DM. As such, the hypothesis suggested is that Vitamin D supplementation (4,000 IU/day) for 24 weeks in pre-diabetic individuals will decrease insulin resistance and the associated metabolic indices linked to the later development of T2DM.